Process of distilling petroleum.



A. S. HOPKl'N-S.

PROCESS or DlSTlLLlNG PETROLEUM.

APPL'ICATION FILED DEC. 18, 1915.

Patented Sept. 26, 1916.

2 $HEETSSHEET I.

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A. S HOPKINS.

PROCESS OF DISTILLING PETROLEUM.

APPLICATION FILED DEC- 18. 1915- I 1,1 99,463. Patented Sept. 26, 1916.

I 2 SHEETS-SHEET 2 HR h, I 11/55/74,551151511 UNITED STATES PATENT QFFIGE,

ALTIS S. HOPKINS, OF NEODESHA, KANSAS, ASSIGNOR TO THE STANDARD OIL COMPANY, OF NEODESHA, KANSAS, A CORPORATION OF KANSAS.

PROCESS OF DISTILLIN'G PETROLEUM,

Specification of Letters latent.

Patented Sept. 26, 1916.

Application filed December 18, 1915. Serial No. 67,602.

relatively heavy or high boiling point hydrocarbon oils to produce therefrom lighter or lower boiling point products,v as carried out, for instance, according to the method disclosed in the patent'to lVilliam M. Burton, No. 1,049,667, of January 17 1913.

' "In the practiceof the Burton process referred to, a liquid body of relatively heavy hydrocarbon oil, such for instance as fuel oil and gas oil, the lightest substantial fractions of which have a boiling point approximating 500 F. is distilled under a pressure of upward of four atmospheres and a temperature of from650 F. to 850 11, whereby such-chemical changes are affected as to result in the production of a distillate of substantially lower boiling point and largely of the desired light, saturated constituents marketable, after suitable-refining, as gasolenei To obtain a maximum yield of the desired distillate in carrying put this Burton process, it is important to make a separation .of the vapors leaving the 'still, immediately condensing and returningto the still for further treatment any fractions of higher boiling point. This separation is sometimes effected by an air condenser in the form of a relatively large upwardly inclining vapor conduit known as a dephlegmator or runback, which is surmounted bya condenser proper comprising a plurality of exposed pipes so arranged as to drain into the runback. From the upper end of this last condenser member the vapors which have escaped condensation pass to the water-cooled coils which drain into a receiver for the distillate'I The use of this apparatus as above described entails aconsiderable heat loss,

the heat units given up in so condensing the Y heavier vapor fractions being dissi ated to the atmosphere, and moreover I' nd tha't changes ofatmospheric conditions so-modify theoperation of these fractionating con- December 18, 1915.

densers as to make it difficult, if not impracticable, to accurately control the process.

, With these considerations in mind I have devised the present process, by which, iii

brief, the following objects are accomplished: The heat units given up in condensing the heavier fractions are utilized to preheat a fresh supply of stock which is to befed to the still for treatment therein. The fractionation of the distilled vapors is controlled with the greatest accuracy and independentlyof weather conditions.

For carrying out my process I prefer to make use of the apparatus illustrated in the accompanying drawings, and which apparatus forms the subject matter of my companion application Serial No. 67,603, filed .In the drawings, Figure 1 is a side elevation, partly in section and partly'diagrammatic, of my improved apparatus,'Fig. 2 is an enlarged broken sectional view of the heat-exchanging condenser of my apparatus, and Fig. 3 is an enlarged section of one side of a modified form of condenser having a thermostatic feed-regulator applied thereto.

Referring to the drawings, the numeral 1 designates the fire-door,.2, the ash-pit door; 3, the firebox, 4, the ash-pit, and 5, a combustion chamber leading into the flue 6 and stack 7 Surmdunting the fire-box and combustion chamber is the horizontal cylindrical still 8, from the upper side.,of which andi'nclining upwardly there leads the dephlegmator, run-back, or vapor outlet pipe 9, at the upper end of which is located the reflu condenserlO. From the upper end of this condenser there leads avapor outlet pipe 11 by which the vapors are carriedgthrough f'a condensing coil 12 mounted in a' water bath 13. A drain pipe 14 carries-"the con"- densed distillate from the coil 12 into, a receivingj drum 15 from which it maybe drawn from time to time by the valved outlet pipe 16. For controlling theescape of the incondensable gases by which the. desired I ,press'ureis maintained upon the still, there is providedja valved escape pipe 17 tapped into-the upper portion of the receiver 15. "l he',detailed construction of the fraction ating condenser 10 is showii by Fig.2, from whichdt cwil-lbe, seen that this member-com} prises a 'substantially-cylindrical verticallyarranged casing orshell 18 intermediatethe.

' length of which there are arranged transverse'tube sheets 19 having tubes 20'-exanded therein. By this construction the interior of the shell 18 is divided into three compartments, a lower compartment 21, which is in communication directly with the run-back pipe 9, an intermediate compartment 22, which lies between the tube sheets 19, and an upper compartment 23, which communicates with. the compartment 21 through the tubes 20 and has tapped thereinto the outlet pipe 11. Near the lower end.

of the intermediate compartment 22 an oil-.

supply pipe 24 is'tapp'ed into the same, this pipe communicating with the pump or other Source of oil under pressure. A hand-don trolled valve 25 and an automatic check-- valve 26' are preferably arranged in the pipe 24 adjacent to the condenser.

Adjacent to the upper end of the compartment 22 a purpose of draining out this sump there is provided a valved drain-pipe 29. A thermometer 30 having its operative portion lying within the upper compartment 23 is preferably extended outwardly through a T-joint in the vapor outlet 11. A second thermometer 31 may be placed in. any convenient location in the pipe 27 V The operation of my apparatus described above is as follows The mixed vapors rising from the still 8 pass outwardly through the dephlegmator 9, which, according to v ordinary practice willbe uninsulated and will, therefore, itself serve to some extent as a fractionating condenser removing the very heavy vapors and returning them to the still. This operation is not necessary whenmy apparatus is employed, however, it being possible to thoroughly insulate the conduit 9, depending wholly upon the condenser 10 for the desired eifect. After passing through the lower vapor compart ment 21 of my condenser, the gases traverse the cooling tubes 20, transferring their heat through the walls of the latter to the oil .within the compartment 22,. the highersboil- "mg-point fractions being thereby condensed andcaused to drain downwardly into the 1 compartment 21 and from the latter through theconduit v9 back to the still to be againsubjected to cracking process. The desired fractions, however, pass through the frac-. tionating condenser in the form of a vapor and by the conduit 11 are carried to the mainifor water-cooled condenser. By the indications iof the temperature as shown by the effect of atmosphere changes.

the thermometer 30, the max imum boiling point of the, -vapors passin this thermome ter may be readily observe ,and by manipulating the control valve 25, thereby increasing or decreasing the flow of cooling'ioil into the compartment 22, the quality of the distillate forming vapor may be changed at will; that is, should the thermometer show a temperature indicating the presence of the objectionable higher boiling-point fractions,

the flow of cooling oil may be increased.

thereby lowering the temperature of the liquid surrounding the vapor tubes 20 and consequently reducing the temperature of and increasing the condensation efl'ectupon the vapors therewithin, causing the higher boiling-point fractions to be liquefied and,

drained backto the still for further treatment therein.

During the process of'distillation, and aci cording to the operation just described, the oil within the compartment'22 gradually moves upward, and entering the upper end 1 of the pipe-27 is conveyed by the latter di- I .rectly into the vapor compartment 21, its temperature at the time 'of itsv entry into .this compartment ranging from 400 F. to

500 F. as indicated. by the thermometer 31. In this latter compartment there prevails 'a temperature considerably in excess of that given, by which the lower boiling-point-fractions of the inflowingoil are converted into i vapor, thelr sudden expansion having a secondary cooling effect on the mixed vapors from the still, thereby lessening the amount of heat to be transmitted through the vapor tubes 20 and increasing the efliciency ofthe' condenser. A considerable .percentage pf this oil is converted into the desired fractions within the compartment 21 itself, while the remainder mixed withthe condensate from the tube i 20' drains back through the conduit 9 to the still for further treatment. a

By. the operation of the apparatus described above I find that the loss of heat is reduced to aminimum, it being possible to thoroughly insulate or jacket both the vapor conduit pipe 9 and the condenser 10 and thereby free the apparatus entirely from 6 1 5 By observing the indications of the thermometer 30 and properly regulating the valve 25, as indicated thereby, it is possible to accurately control-the boiling point of the distillate reaching the* receiver 15, and to counteract the effect of uneven firing under the still 8. The fresh stockfed into the' pipe 24 is so thoroughly preheated during its passage through the compartment 22 that upon entering the vapor compartment 21,

all of the desired lighter fractions which it may contain are vaporized and there is reason to belleve, moreover, that a certain limited amount of cracking takes place within this-chamber also. Since all of the oil fed in by the pipe 24 is in effect added to the charge of the still, it will'be seen that the capacity of the latter is increased to this extent, and since the quantity of fuel required and the time for completing a run of the still does not increase proportionately, it may be said that by my process the efficiency as well as the capacity of the distilling apparatus is increased.

In Fig. 3 of the drawing I have shown means by .which the "valve 25 and consequently the inflow of fresh oil through the pipe 24 may be automatically controlled in accordance with changes of temperature in the upper vapor compartment 23. In the construction shown in Fig. 3 there is mounted Within this vapor compartment a thermostat 32 of anyapproved design and arranged to operate electrical contact devices by which the starting, stopping and re versal of an electric motor 33 is controlled. This motor may be caused to actuate the valve 25 as by providing the latter with a worm-wheel 35 for engagement with aworm 34 driven from the motor 33. By this construction thethermostat 32 may be set for a certain pre-determined temperature, this temperature being the vapor temperature at which the maximum quantity and the best quality of distillate is obtained in the receiver 15, and the thermostat will then act through its electrical connection to open the valve 25 and increase the flow of cooling oil when the temperature of the Vapors in the compartment 23 tends. to exceed the predetermined maximum, or, by reversal of the motor 33, will close the valve 25 as'the temperature of thevapors in the comp-artment'23 tends to drop below the desired minimum.

While I have described in, considerable detail the preferred method of carrying out my improved process, it is to be understood 1". The process of treating petroleum ing the vapors passing the said condenser.

2. The process of treating petroleum hydrocarbons having a boiling point ofup ward of 500 R, which consists in distilling a liquid body of the said hydrocarbons under a pressure of upward of 4 atmospheres and a temperature of from 650 to 850 F., leading the mixed vapors of distillation from the still through a vapor line to a reflux fractionating surface condenser in which the still pressure is maintained, cooling the surfaces of the said condenser by supplying thereto a fresh and unheated stock of a similar petroleum hydrocarbon, whereby the latter becomes heated, leading the mixed stream to the still through the vapor line, mixing this heated fresh stock with the refiux condensate, and carrying off and separately condensing and collecting the vapors passing the said condenser.

3. The process of treating petroleum hydrocarbons having boiling points of upward of 500 F., which consists in distilling a liquid, body of the said hydrocarbons under a pressure of upward of 4; atmospheres and under a temperature of from 650 to850 F., leading the mixed vapors of distillation from the still through a vapor line to a refluxfractionating surface condenser in free communication with thesaid still, cooling the surfaces of said condenser by supplying thereto a fresh and unheated stock of the said hydrocarbons, whereby the latter becomes ,heated, mixing the said heated stock with the reflux condensate, leading the mixed stream to the still through the vapor line carrying off and separately 3 condensing and collecting the vapors passing thesaid condenser, and regulating the ALTIS S. HOPKINS.

In presence of J. D. GONDT, E. A. METCALF. 

